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(ModeL) G. H. PRESTON.

WOOD BENDING MACHINE.

Patented Mar. 7.1882.

UNITED STATES PATENT OFFICE.

GEORGE H. PRESTON, OF SHQRTSVILLE, NEW YORK.

WOOD-BENDING MACHINE.

SPECIFICATION forming part of Letters Patent No. 254,568, dated March '7, 1882,

Application filed November 12, 1881. (ModeL) To all whom it may concern:

Be it known that I, GEo. H. PRESTON, a citi- .zen of the United States, residing at Shortsher-such asfellies,shafts,poles, &c.as well as light, bending without splitting, breaking,

or buckling the timber.

Figure l of the drawings is a perspective view of a bending-machine of the Blanchard style with myimprovement applied. Fig.2 is a view of my improvement or spring-follower as it is applied to the bed or table which forms the bending-lever of the machine. Fig. 3 is a view of the spring-follower with threeadjusting-bolt-s instead of one, as shown in Figs. 1 and 2. y

The part marked H of the drawings is the shaft, upon which the form B is placed for operation. The shaft H is usually turned by means of gears, but the cranks G will do to illustrate. v

E is the bed, arranged so as to slide endwise backward and forward under the form B. The hard J in the end of the strapAis made to fit into hooks P P in the bed E.

The follower D is made of wood, and is for the purpose of receiving the pressure from the spring-follower and communicatingit squarely against the end of the bending stick. The spring-follower (shownin Fig. 2) is constructed of two heads, I I, the bolt 25, the nut K, and the spring S. The heads I I are connected together by the boltt, runningthrough the spring S. Two or more bolts may be used instead of one for this purpose, as shown in Fig. 3 of the drawings; but as the tension of the spring is controlled by this bolt,and as the tension must be changed when heavier or lighter timber is to be bent, it is more convenient to adjust with but one nut. The spring-follower is'arranged upon ways or guides in the bed E, and when the pressure is off is free to move bodily backward and forward upon its guides.

The pressure upon the end of the timber is sometimes produced by means of a cam, sometimes by a wedge, and sometimes by a screw,

all of which are old devices; but the screw is the mostefticient, which is shown at F. In other machines the pressure by the screw, cam, or wedge is applied directly to the follower D, which commnicates the pressure to the timber to be bent, and is unyielding; but by placing the spring-follower between the pressure and the timber G the timber is allowed to adjust itselfendwise sufliciently to make a perfect bend, and neither break nor buckle.

The operation of the machine is as follows: Place the form B (the strap A being attached to it) upon the shaft H, with the strap fastening directly at the bottom. Draw the bed E back so far that the bar J J will engage with the hooks P P. Place the timber Gupon the strap A, with one end under the form, and place the follower D in its place against the other end of the timber. Apply a pressure to the spring-follower by turning the screw F sufficiently to loosen the nut K. If the tension of the spring is not right it may now be adjusted by turning the nut K. It may be seen that the screw F will hold the spring to its proper tension while bending; but the bolt t prevents'the spring from exganding when the screw is turned back, thereby saving the labor of turning the screw to compress the spring at each operation. When commencing to bend see that the pressure applied by the screw F is suflicientto loosen the nut K. The form may then be turned'till the timber is bent without any further attention to the upset.

A fiat steel spring with one or more angles GEO. H. PRESTON.

Witnesses CHAS. EDGERTON, FRANK S. BInwELL. 

